Plate-type heat exchangers are used for certain industrial applications in place of fin and tube or shell and tube type heat exchangers because they are less expensive and easier to make than most forms of heat exchangers. In one form of such plate-type heat exchangers, a plurality of primary surface plates are brazed together in a unitary structure with spacer frames located between adjacent plates and traversing a course adjacent to the plate peripheries. Flow of the two fluids involved in heat exchange is through alternate layers defined by the brazed plates. The space between the plates may be occupied by protuberances or fins formed in the plates to increase turbulence or heat exchange in the fluid flow. All of the fluid flowing in a given defined space is in contact with the plates to enhance heat transfer.
In order to handle larger heat loads, existing plate-type heat exchangers may be scaled up in size by adding more layers or using denser configurations of layers. However, one problem that arises with some designs is that the pressure loss across the heat exchanger increases. One technique used to decrease the pressure loss is to transversely supply each layer from a single conduit. The conduit is sized to minimize any pressure drops. An example of such a heat exchanger is disclosed in U.S. Pat. No. 5,911,273 to Brenner et al. (“the '273 patent”). The '273 patent discloses a heat exchanger having a stacked plate construction made of four distinct parts: a cover, a flow duct plate, a connection cover plate, and a connection plate. These parts are alternated and rotated in a stack assembly. A first fluid flows into the heat exchanger through a connection opening, into a single connection conduit, then transversely through fluidically parallel layers. A second fluid has a similar flow pattern, with the heat exchange occurring across the parallel layers of the stack assembly.
While the configuration of the '273 patent attempts to decrease pressure losses, it results in an increased manifold volume or supply conduit volume to heat exchanger volume ratio. As the size or the number of layers in the heat exchanger increases, the size of the manifold volume increases as well. For applications requiring a compact construction, this may prove to be unacceptable. In addition, there may be non-uniform heat exchange such that layers farthest from the supply conduit inlets may receive less flow than layers closest to the supply conduit inlets.
The present disclosure is directed to overcoming one or more of the problems set forth above.